1. Field of the Invention
The present invention relates to a magnetic separator containing magnetic blocks which are magnetized in a drum uniformly and perpendicularly relative to the axis of the magnetic separator.
2. Description of the Prior Art
Such magnetic separators are utilized for dry-field or wet-field separating wherever a field that can be generated with permanent magnets is adequate. In drum-type magnetic separators, the magnetic field is stationary and the product to be separated is moved over a region of the drum as disclosed in the German application No. 32 38 052 A1, and the German allowed application No. 28 32 275.
The force for separating magnetic from unmagnetized particles in the dry-field and wet-field separation depends on the absolute quantity and on the gradients of the magnetic field strength. A maximally-high, maximally-uniform magnetic field strength is generally a favorable pre-condition. However, the range is also critical for the performance of a magnetic separator, this being essentially dependent on the field gradients and, among other things, having influence on the maximum grain size of the product to be separated.
U.S. Pat. No. 3,365,599, fully incorporated herein by this reference, has proposed to improve the magnetic flux in the outer region of a magnetic drum in that the interspaces of radially-magnetized segments (the north poles and south poles of the magnetic separator) be partially bridged by magnet blocks magnetized in the circumferential direction. The magnetism "wasted" due to the mutual de-magnetization is thereby also supposed to be capable of being exploited. However, it is not true, as occasionally maintained, that the "overall magnetism is conducted into the work region of the drum" as a result thereof.